Aluminium engine detailing

[axeman74]

OK, this is my first post to the Alfa BB, so please be gentle

I am restoring a '74 GTV 2000. I am rebuilding the engine at the moment, and am putting lots of work into the detail of the engine- zince plating all fitting and fasteners, powdercoating mounts/pulleys/camcover etc, all new rubber parts and so on. I would like to get the nice new finish back on the aluminium parts of the engine- block, head etc. What is the best way to do this? I have tried polishing with Autosol, but this does not remove the dirt and grit trapped in the pores of the casting. I do not want a polished finish, but would like to restore the original dull silver/grey finish on the aluminium. I am a real fussy bastard (as you will probably learn in my future posts), and really want to get these components looking good as new.

So can anyone recommend any chemicals or techniques for achieving this? I would imagine the chemical used in traditional engine shop "acid tanks" would be far to harsh for alfa's aluminium?

Any ideas appreciated.

Axeman

[conedriver]

Hi Axeman,

Welcome to the BB. This is a great opportunity to share information.

Several years ago, I had a head rebuilt by Sperry Valve Works and it was returned having been glass bead blasted. This finish was not exactly original, but is a nice soft silver/grey color, is uniform over the entire casting, and cleans easily using mild spray-on Gunk Foamy or Citrus cleaner (NOT the original "smelly" Gunk). This process may be too late for your purposes if you are re-assembling the engine. If one were to start over you would want to do this to all of the aluminum castings to achieve uniform appearance.

Please post pictures as you progress on the GTV. And, where are you located?

Quote:

Originally Posted by axeman74 OK, this is my first post to the Alfa BB, so please be gentle I am restoring a '74 GTV 2000. I am rebuilding the engine at the moment, and am putting lots of work into the detail of the engine- zince plating all fitting and fasteners, powdercoating mounts/pulleys/camcover etc, all new rubber parts and so on. I would like to get the nice new finish back on the aluminium parts of the engine- block, head etc. What is the best way to do this? I have tried polishing with Autosol, but this does not remove the dirt and grit trapped in the pores of the casting. I do not want a polished finish, but would like to restore the original dull silver/grey finish on the aluminium. I am a real fussy bastard (as you will probably learn in my future posts), and really want to get these components looking good as new. So can anyone recommend any chemicals or techniques for achieving this? I would imagine the chemical used in traditional engine shop "acid tanks" would be far to harsh for alfa's aluminium? Any ideas appreciated. Axeman

[ossodiseppia]

Quote:

Originally Posted by axeman74 So can anyone recommend any chemicals or techniques for achieving this? I would imagine the chemical used in traditional engine shop "acid tanks" would be far to harsh for alfa's aluminium?

[jrflyboyVP2]

I used a phosphoric etch the same as used on aircraft aluminum prior to painting. I had some left over from stripping and painting my Mooney. I just brushed it on the outside surfaces let it sit, than rinse off with water. I recommend the cream since it sticks to vertical surfaces better. The part has to be degreased first though. The etch won't cut through oil or greasy surface. Clean with a good solvent like MEK first. You can get it at many different aircraft supply houses like aircraft spruce and speciality www.aircraft-spruce.com Specifically: http://www.aircraftspruce.com/catalo...pfcleaners.php

I used:
ALUMA-DYNE E-2311 ETCHING
AND BRIGHTENING CREAM
Qt. P/N 09-40550 $14.10

Regards, John

[Touringspider]

Welcome to the bb. Fussy ones unite!

Your options are obviously greater if the engine is completely dismantled. When I rebuilt my last aluminum engine, the machine shop put the head and block into what can best be described as a giant high pressure washing machine. The components came out looking like new.

One thing you might try at this stage is to use a soft brass cup brush on a pneumatic drill or die grinder to work the Autosol into the rough areas of the casting. You could then finish it up using some of the various sizes and shapes of buffs that Eastwood sells.

Arno Leskinen
AROC-USA National Concours Chair
102
115
116

[PSk]

When you rebuild carburetters (my fathers garage used to rebuild carbs as a bit of a specialist, secondary to the normal car repairs) the bodies are cleaned by acid dipping in some toxic chemical. They come out looking absolutely brand new ... after a good rinse with water.

I cannot see why the alloy components of an Alfa Romeo engine could not use the same process ... or though you would need a much bigger tank.

I'll ask my father what the chemical/acid, etc. is.

Pete
ps: If you do blast ... make sure you dip in something like kero and spend absolutely ages cleaning the components ...

EDIT response:

Quote:

Originally Posted by My father From memory it was called Carburosol and came from the Auckland Gas Company. A relation of Tergosol [an industrial cleaner]. So therefore these products were probably by-products of making gas fron coal? No doubt when cleaning any type of metal you have to know what matter you want to dissolve and use the appropriate product. This Carburosol was magic at removing caked on grease/dirt from carburettors. It would also remove the skin from your bones given time. It also softened rubber so we had to be careful that only metal parts went in.

[Larry G]

A possible alternative might be Eagle One brand 'Aluminum Wheel Wash'. It's made for cleaning rough cast finish aluminum wheels. Has a mild etching action and does a fine job on wheels. Should work on other castings. Has anyone tried this?? It's available at auto accessory stores like Autozone, etc.

Larry G

[evanbottcher]

There was an article in our local club magazine about a twin spark conversion, the author highly recommended eagle one wheel cleaner for removing EVERYTHING from the block inside and out during the rebuild.

cheers,
Evan.

[ossodiseppia]

Quote:

Originally Posted by PSk When you rebuild carburetters (my fathers garage used to rebuild carbs as a bit of a specialist, secondary to the normal car repairs) the bodies are cleaned by acid dipping in some toxic chemical. They come out looking absolutely brand new ... after a good rinse with water.

[Touringspider]

I have said this before in another thread, but carb cleaner makes a great rinsing agent when you degrease engines. Use one of the degreasing products and a suitable agitating device (brush etc) to loosen and remove the major stuff, and then follow it up with pressurized carb cleaner. Repeat until you are satisfied with the results. The carb cleaner really gets at the stuff the degreaser leaves behind. Liberally rinse with water as your final step and properly dispose of all your waste.

Arno Leskinen
AROC-USA National Concours Chair
102
115
116

[axeman74]

Thanks to everyone that responded. Hope the good suggestions continue for my future posts.

I have tried several methods of cleaning the aluminium, including Autosol polish, oven cleaner, paint stripper and paint thinners. These helped to varying degrees, but I am still having trouble getting the dirt out of the pores and restoring the finish, especially on the block. Next step will be to try carby cleaner, and a product i found at the local parts store called "Alubrite".

A couple of people suggested using "eagle One" mag wheel cleaner. I recall years ago watching my older brother clean the rough sandcast wheels on his Holden with a combination of eagle one wheel cleaner and an old toothbrush. The results were excellent. However I am told that with most wheels being clear coated nowadays, eagle one has reduced the potency of the product so as not to destroy the wheels finish. I will buy some and give it a go anyway.

I have also found a local company that specialises in chemically stripping timber and metal items, and will be seeking their advice tommorow. I would certainly welcome any other suggestions.

By way of introduction, I am located in Melbourne, Australia. I will attach some current pics of my car and engine in question tommorrow.

Thanks again,

Axeman74

[GTV67]

Eagle One Etching mag wheel cleaner works great on the outside of Alfa-blocks - for some reason it doesn't seem to touch the alloy that the front timing covr is made from - I ended up painting that.

Also - a wire brush on a die grinder will probably get the best shine - just be firm but gentle.

I was warned off glass bead blasting on the engine - just not worth the risk - it will get somewhere you don't want it and may never come out - can destroy a new engine really fast - only use on parts you can see into every orifice of.

-Richard